What happens when a Pin<Box<T>> binding is moved to another variable?

What happens when a Pin<Box<T>> binding is moved to another variable?

1. The pointer handle moves, while the T in the Box allocation stays at its address.
2. Both the handle and T are copied byte for byte to new addresses.
3. The assignment is rejected whenever T is !Unpin.
4. T is dropped before the new binding is initialized.